First there was the news that students in American universities study a lot less than they used to. Now we hear, in a recent book titled Academically Adrift, that 45% of the nation's undergraduates learn very little in their first two years of college. ... Have colleges, in their efforts to keep graduation rates high and students happy, dumbed down their curriculums? If they have, who is to blame? What should parents and federal taxpayers do?